Currently, the incidence of thyroid cancer is increasing year by year and has become the 5th most common malignant tumor in women. The cause of thyroid cancer is not very clear. It may be related to dietary factors, history of exposure to emission lines, increased estrogen secretion, genetic factors, or other benign thyroid diseases such as nodular goiter, hyperthyroidism, thyroid adenoma and especially chronic lymphocytic thyroiditis. Ultrasound can be very helpful in the diagnosis of differentiated thyroid cancer. Most of the differentiated thyroid cancers are substantial masses on ultrasound, but some of them can be mixed masses with predominantly parenchymal components. Papillary thyroid carcinoma is mostly hypo- or very hypoechoic on ultrasound, with microcalcifications or gravel-like calcifications in the parenchyma and no posterior acoustic shadowing; the mass may also be morphologically abnormal, appearing in a vertical or upright position, with abundant blood supply around the mass. Follicular carcinoma of the thyroid gland is usually a very homogeneous hyperechoic mass with rich blood supply in ultrasound. The size of the mass, whether the boundary is clear, whether the shape is regular, and whether there is an acoustic halo around the mass are not important indicators to determine whether the mass is malignant. Therefore, ultrasound findings of vertical, microcalcifications or gravel-like calcifications in thyroid masses should be taken seriously for early diagnosis and treatment.